Aluminum nuggets are used in the steel making industry as a deoxidizing agent and to remove impurities. As is known, basic oxygen furnaces or electric arc furnaces are used to produce steel by removing the carbon content of the molten iron using oxygen lance. Iron oxide fumes are produced causing a weight loss in the steel produced and a waste disposal problem. When aluminum is added during the steel making, such as in the form of nuggets, it reacts with the iron oxide fumes to form an exothermic reaction generating large quantities of heat and deoxidizes the iron oxide fumes into molten iron while the aluminum is oxidized into aluminum oxide.
The forming of a molten aluminum layer over the iron and slag surface is important to maximize the reaction and obtain a higher yield. The aluminum layer floats on the top of the molten steel and blocks communication between the top of the molten steel and ambient air to tend to prevent undesired oxidation of the steel. Thus, aluminum bodies of relatively uniform weights and shapes (herein referred to as nuggets) are used for easy handling and to provide a relatively controlled amount of or generally uniform dispersion of molten aluminum needed during steel production.
A number of conventional machines have been used to produce aluminum shapes (nuggets) using a pouring mechanism that tilts a ladle by mechanical or hydraulic means to fill multiple cavities in each mold. Once the cavities are filled, the mechanism retracts to a non-pouring position and prepares to pour into the next mold. Another conventional approach has been to pour aluminum into cavities of special design molds using a tundish with bottom pouring orifices. Unfortunately, these mechanisms and the special configurations of the molds have impeded the capability to produce large quantities of aluminum shapes at reduced costs.
As an example, U.S. Pat. No. 3,512,575 discloses a method and apparatus by which the aluminum shapes are produced by using a ladle tilting mechanism to fill the mold cavities and which retracts after the cavities are filled. These motions are repeated with every mold that passes underneath the filling mechanism.
U.S. Pat. No. 3,964,542 discloses a method and apparatus by which the aluminum shapes are produced by pouring molten aluminum into cavities and using a tundish with bottom orifices. The molds are specially arranged to prevent metal from bridging over from cavity to cavity.
U.S. Pat. No. 2,199,598 discloses a method and apparatus by which the molds are filled using a supply pipe for liquid metals to a pouring wheel with a discharge orifice. Each orifice is advanced by the successive molds as the molds are advanced beyond the pouring station.
In view of the aforementioned shortcomings associated with conventional systems, there is a strong need in the art for a system for producing aluminum shapes having uniform weight and shape at a high production volume and at a reduced cost. Moreover, there is a strong need in the art for a system which prevents splashing of molten aluminum or bridging of metal between mold cavities.